296 GEORGE D. HUL8T. 



liarities. A very common, iind perhaps the most remarkable of 

 these, is the tendency of the hind legs to obsolescence, in part or as 

 a whole. The spurs are often partly or altogether absent. Some- 

 times the hind tibine are largely developed with heavy hair pencil in 

 the males, the tarsi being much shortened, and again the wliole leg 

 is sometimes practically obsolete in the males. The development 

 seems to have been as follows : The hair pencil has developed on the 

 hind tibite, and, with its increased develo[)ment and use for orna- 

 mentation, the spurs and tarsi have been absorbed, so that the hind 

 legs have become useless for their normal purpose. A change of 

 development then seems to have taken place ; the pencil has been 

 gradually aborted, and the leg being useless for its normal purpose 

 has tended to become obsolete. I have found no instance where the 

 leg is absolutely wanting, but there are many where it is very de- 

 cidedly reduced. This tendency, also shown auiong the Geometrinse, 

 is, so far as I know, unique among the Lepidoptera. 



In this family the tongue is always developed, the fore tibiae are 

 never clawed, and the clypeus never tubercled. The venation of 

 the fore wings is to an extent variable, but the number of accessory 

 cells is rarely subject to variation. A peculiar feature is the ab- 

 normal and deltoid development of the })alpi in a few species. 



Of the typical genus Sten-ha Hiib., of which Acidalla Treit. is a 

 synonym, I have as yet found no representative in our fauna. 



STERRHIN^. 



Synojisis of Genera. 



1. Hind tiliiie of 9 with nijjier spurs present 2. 



Hind tibise of 9 with ujjper sjjurs absent 13. 



2. Hind tibiie of % with end spurs jjresent 3. 



Hind tibia^, of % witli end spui's absent 9. 



3. Hind tibiie of % with upper si)urs present 4. 



Hind tibiie of % witli U])i>cr spurs absent 6. 



4. Palpi long 5. 



Palpi nioderHte 1. Calotliysaiiis. 



5. Palpi very long, deltoid ; fore wings 10 on 9 5. i^IyC'ttM'opliora. 



Palpi long, fore wings 10 on 11 1. Prowaparia. 



(i. Antennse of % bipectinate 7. 



Antennae of % not bipectinate 8. 



7. Fore wings with accessory cell 7. I^eiicoplillialiiiia. 



Fore wings without accessory cell (). Oeplaliii. 



8. Fore wings with accessory cell 10. Ciiigliw. 



Fore wings without accessory cell 17. !iig<'la. 



